But in the 11th they did, as Luis Gonzalez led off the frame with a double off the left-field wall on a cut fastball by Andy Pettitte. The fact that the lefty was pitching in relief for the Astros caught the sellout crowd and even the D-Backs off guard.

"In our scouting [report], they only had one lefty in their bullpen," Gonzalez said, referring to Trever Miller, who pitched the eighth. "I looked back at [Melvin] when I was on deck, and I said, 'Who's that left-hander?'"

It was Pettitte, who was scheduled to throw a bullpen session on Friday in between starts. With the game in extra innings and his bullpen depleted, Astros manager Phil Garner went to the veteran.

"Garner caught us off guard with that one," Gonzalez said.

Pettitte, though, is no stranger to the D-Backs, and they knew exactly what they were going to see from him: cutters and sliders away with the occasional inside fastball to keep the hitters honest.

"With him you just try to see it and make adjustments as you go on," Gonzalez said. "I've been seeing the ball real good as of late and I just got a pitch out and I drove it to left field."

That was the get 'em on part of the equation, and Chad Tracy came through with the get 'em over part when he followed with a ground ball to the right side of the infield that moved Gonzalez to third.

That brought up Johnny Estrada, who has been the club's best clutch hitter this season. A switch-hitter, Estrada dug in on the right side of the batter's box.

"I'm a little surprised they pitched to me," he said. "I thought they might put me on and pitch to Greenie [Shawn Green] since he's left-handed."

Estrada normally waits until he has two strikes to choke up on the bat, but against Pettitte he went right to it.

"I know he has a good cutter and he usually throws cutters into righties and is pretty good at it," Estrada said. "So I just choked up on the bat there and just tried to drive something to the outfield to get Gonzo in."

Estrada lifted a fly to the warning track in left to bring home a tagging Gonzalez with the go-ahead run.

Then there was the little matter of shutting the Astros down in the bottom of the 11th. That was no slam dunk, given the way the game had see-sawed all night. Arizona led, 3-0, before rookie outfielder Luke Scott tied things up with one swing of the bat in the fourth.

Scott was a thorn in the D-Backs side all night long, as he managed to hit for the cycle while driving in five runs.

"We couldn't get that guy out," Estrada said. "We threw him everything and the kitchen sink today. He was just spitting on the bad pitches, being patient up there and hitting the ball all over. "

The D-Backs then built a 7-4 lead, thanks in part to a pinch-hit two-run homer by Carlos Quentin in the seventh off Chad Qualls. It was the fourth homer for Quentin in 16 at-bats since being called up a little more than a week ago.

"He did it again," Melvin said. "Boy, it seems like he's getting quality at-bats and big hits for us since the day he got here. [Hitting against Qualls is] no day at the beach. [Qualls is] pretty darn good."

But that lead didn't last either, as the Astros scored two in the bottom of the seventh and one in the eighth -- thanks to an error by shortstop Stephen Drew -- to tie the game.

While Quentin played a key role on offense, another rookie was equally important on the mound. Right-hander Tony Pena came on in the 10th and pitched two scoreless innings to pick up his second win.

The bottom of the 11th wasn't without its anxious moments for Arizona, though, as Scott singled with two outs to bring the winning run up in the form of pinch-hitter Lance Berkman.

But Pena got two quick strikes on Berkman before the count went full, and Berkman wound up grounding out to first to end the game.

"That was a big two innings from the kid," Estrada said. "That was impressive."

Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.